The invention pertains to the field of supercharger. More particularly, the invention pertains to supercharger having pressure aided oil drain.
Superchargers are frequently belt driven and have gears in a gear case to substantially gear up the rotational speed so that the compressor of the supercharger will generate sufficient boost. In presently available superchargers, the space inside the gear case is purposely made relatively large, with much space between the gears and the walls of the gear case so that oil can be flung or spread onto the various gears and bearings therein. However, one side effect of large cases is that larger space is required. This is undesirable in that given the reduced size requirement of some engine design, a more compact form factor is required.
U.S. Pat. No. 6,293,263 to Middlebrook, which is incorporated herein by reference, discloses a compact supercharger having a drive portion, and an atomizer for providing a lubricating oil/air mist to the supercharger. The drive portion has a drive gear with teeth and an outer circumference and a driven gear with teeth and an outer circumference, drive gear bearing races and driven gear bearing races, and a gear case with an inner chamber with a back wall, a front wall, perimeter walls having a swale formed thereon. The drive gear is larger than the driven gear and is positioned below the driven gear. Drive gear bearing mounting recesses receive the drive gear bearing races, and driven gear bearing mounting recesses receive the driven gear bearing races. An oil/air mist inlet is formed in the gear case, and oil/air mist channels are in communication with the oil/air mist inlet and the driven gear bearing races. A splitter with passageways is located near a bottom of the gear case in the vicinity of an oil outlet. The outer circumference of the drive gear is in close proximity to the perimeter walls of the inner chamber and an upper face of the separator portion. During rotation of the drive gear, oil/air mist will be expelled against the perimeter wall portion to aid in separating the air from the oil, the oil will travel down the swale, through the passageways of the splitter, and exit through the oil outlet, thereby preventing windage of the oil in the gear case and assisting in power draining of oil from the gear case.
As can be seen, Middlebrook uses compressor discharge air to atomize incoming oil to create an oil/air mist for lubrication purposes.
Although there has been a substantial amount of development work on more efficient designs for superchargers, there remains a need for improved superchargers that are more compact in design, are better lubricated, and that are more durable, more efficient, and readily installable onto different engines.
In a centrifugal supercharger that does not have a self contained oiling system, a compact gear box is provided having a pressure aided oil drain.
In a centrifugal supercharger that does not have a self contained oiling system, a compact gear box is provided in that the size of the gear box cavity being more closely approximate the size of the gear set envelope.
In a centrifugal supercharger that does not have a self contained oiling system, pressurized air is introduced into the gear case of the supercharger, wherein the pressurized air is obtained from the discharge side of the compressor housing.
Accordingly, a compact supercharger having a compressor end and a drive portion is provided. The compressor end includes a volute and a compressor wheel. The drive portion includes: a drive gear having an outer circumference and a driven gear having an outer circumference, the drive gear adapted to engage with the driven gear, the driven gear having a driven gear shaft adapted to connect to the compressor wheel, and the drive gear having a drive gear shaft adapted to rotate the drive gear. The compact supercharger includes: a gear case encompassing the drive gear and the driven gear, the gear case having at least one oil inlet in the gear case to receive oil, and at least one oil outlet on the gear case. An air passage is provided which has a first end connected to the compressor end down stream in relation to the compressor wheel, and a second end connected to the gear box, whereby pressurized air at the compressor end is disposed to be channeled toward the inside of the gear box for draining lubricating fluid therein.
In a compact supercharger having a compressor end and a drive portion, the compressor end including a volute and a compressor wheel, the drive portion including: a drive gear having an outer circumference and a driven gear having an outer circumference, the drive gear adapted to engage with the driven gear, the driven gear having a driven gear shaft adapted to connect to the compressor wheel, and the drive gear having a drive gear shaft adapted to rotate the drive gear. A method including the steps of: providing a gear case encompassing the drive gear and the driven gear, the gear case having at least one oil inlet in the gear case to receive oil, and at least one oil outlet on the gear case; providing an air passage having a first end connected to the compressor end down stream in relation to the compressor wheel, and a second end connected to the gear box, whereby pressurized air at the compressor end is disposed to be channeled toward the inside of the gear box for draining lubricating fluid therein; and using pressurized air coming through the air passage to evacuate the gear cavity to a sump of lower pressure.